How to troubleshoot slow speeds
 

During the day my speeds are in excess of 100M but in the evening it drops to between 40-60M.

I don't download anywhere near enough to activate STM so is it just down to oversubscription?

Re: How to troubleshoot slow speeds
 

In all probability, yes. There can be other causes (in the network) that manifest themselves when there is heavy load - these are sometimes indicated on a Thinkbroadband.com/ping graph by showing dropped packets that might be down to upstream line noise.

It would help if you posted a daytime/peaktime TRACERT www.bbc.co.uk. Also set the TBB graph going and in any case post your power levels, as you never know what can be deduced.

But dropping to the 40-60 meg range seems to me to be a peak time likelihood.